To get the engine running I give the needle valve two and a half turns, stick the glow stick on the start it with the electric starter. it usually starts right up, although sometimes it takes a time or two before it starts.
My guess is herein lies the problem. After you start the engine, you need to readjust the high speed needle to achieve peak rpm at max throttle, probably by turning it in (clockwise), and then turn it back out (richer) 2-3 clicks At 2 1/2 turns, your probably running the engine VERY rich, and it wont come anywhere close to providing good power. As this is your first engine, get someone to help you and show you how its done. Its not difficult.
Once you have it tuned, you shouldn't need to mess with the high end needle unless there is a large change in temperature or humidity. The 2-1/2 turns is usually recommended for new engines to make sure they are not run lean when first started.
Brad